1. Field of the Invention
The present invention relates to a wide screen display for a TV set, and in particular to an automatic wide screen display method and apparatus for a TV set capable of automatically displaying a wide screen image and controlling deflection of a color picture tube (hereinafter, CPT) by self-detection of an aspect ratio of an input video signal.
2. Description of the Conventional Art
FIG. 1 is a block diagram of a conventional wide screen display TV set. As shown therein, the conventional wide screen display TV set includes an antenna ANT for receiving high frequency video and audio signals transmitted from a broadcasting station where the video signals have an aspect ratio of 4:3, a tuner 11 for receiving the high frequency video and audio signals from the antenna ANT and outputting high frequency input video and audio signals VD1, AD1, a main microcomputer 13 for controlling the tuning operation of the tuner 11 and outputting a switching control signal SC in accordance with an input screen selection signal IS outputted from a remote control 12, an audio/video switching unit 14 for selecting and outputting a single signal among the input video and audio signals VD1, AD1 outputted from the tuner 11 or external input signals EXT1-EXT3 in accordance with the switching control signal SC, an integrated deflection device 15 for detecting color signals R, G, B of a baseband output video signal VD0 selectively outputted from the audio/video switching unit 14 and thereby outputting the color signals R, G, B to a CPT, and an integrated sound processing device 16 for detecting left and right stereo audio signals from an output audio signal AD0 selectively outputted from the audio/video switching unit 14 and thereby supplying the left and right stereo audio signals to left and right speakers SPL, SPR.
The operation of the conventional wide screen TV set display will now be described.
A high frequency video signal with the aspect ratio of 4:3 and an audio signal transmitted from a broadcasting station are received by the antenna ANT of the TV set and then supplied to the tuner 11, and the tuner 11 outputs intermediate frequency video and audio signals to the audio/video switching unit 14.
External input signals EXT1-EXT3 outputted from a video or an audio player, such as a laser disk player LDP or a VCR, are supplied to other input terminals of the audio/video switching unit 14.
Accordingly, when a user inputs to the main microcomputer 13 an input selection signal IS by using the remote control 12 or a key matrix, the main microcomputer 13 controls the switching operation of the audio/video switching unit 14 in accordance with the input selection signal IS, and the audio/video switching unit 14 selects and outputs a single signal among the input video and audio signals VD1, AD1 outputted from the tuner 11 or the external input signals EXT1-EXT3.
The output video signal VD0 selectively outputted from the audio/video switching unit 14 is converted to baseband color signals R, G, B by the integrated deflection device 15 to be displayed on the CPT, and the output audio signal AD0 is supplied to the left and right speakers SPL, SPR through the integrated sound processing device 16.
For example, if the user outputs a wide mode selection signal by using the remote control 12, the main microcomputer 13 acknowledges the wide mode selection signal and controls deflection of the integrated deflection device 15, whereby a wide screen image is displayed on the CPT.
However, in the case where a video signal having a certain aspect ratio is desired to be displayed on the entire wide screen of a general TV set provided with the wide screen display function, the user has to manually change the wide mode selection key and, when the aspect ratio of inputted video signal is changed, the wide mode selection key has to be operated manually to adjust the aspect ratio for displaying the inputted video signal, thereby causing inconvenience. In addition, since the wide mode of a conventional TV set is limited to such as a 4:3 mode, a spectacle mode, a wide mode, a zoom 1 mode, and a zoom 2 mode, etc., depending upon the aspect ratio, various screen displays can not be achieved.